STRATIGRAPHY OF NORTHERN BELIZE

Belize, formerly British Honduras, has a thick Coastal Plain section composed of exposed and subsurface Mesozoic and Cenozoic strata. Since preparation of the relatively extensive 1952 stratigraphic study by G. Flores, which was written for the Bahamas Exploration Company, Ltd., no further detailed analysis of all stratigraphic units has been conducted in the northern area of Belize. Flores described all stratigraphic units in Belize as informal. In 1986, a provisional geological map of Belize (1:250,000) was produced for the Petroleum Office of the Ministry of Natural Resources by J. Cornec. This mapping effort did not include formalized stratigraphy either. At present, Belize has no formal stratigraphy and there are no type localities for any of the informal stratigraphic units. Our experience in Belize, working in the interior of the country north of the 17th parallel, has been that the provisional geological map has several deficiencies and that stratigraphic nomenclature can be confusing. For these reasons, we are presenting here a discussion of the main stratigraphic units of northern Belize, with a description of each, their provisional type localities, and pertinent references. The stratigraphy consists of (1) a thick section of deformed and metamorphosed Carboniferous-Permian sedimentary and volcanic strata in the Maya Mountains, (2) a moderately thick section of Mesozoic strata, mostly carbonates, which are found in the subsurface and in outcrop near the Maya Mountains and along major faults, (3) rare exposures of Chicxulub impact ejecta overlying Upper Cretaceous carbonates, and (4) a relatively thin section of Paleocene-Pleistocene carbonates, which comprise most of the coastal plain of northern Belize. All of the currently recognized stratigraphic units of Belize are informal and most lack true type sections and proper descriptions. This research attempts to discuss and synthesize what is known of the stratigraphy of this region.